#define gpiob1_odr_addr *(unsigned int *)0x40020414

void delay(int a)
{
    while(a --);
}
#ifdef __GNUC__
int main(void)__attribute__((section(".isr_vectors")));
#endif

// volatile int my_variable = 10;
volatile int value2  = 11;

int main(void)
{
    if( value2 != 11 ){
        gpiob1_odr_addr &= ~(1 << 1);
        return 1;
    }
    while(1)
    {
        gpiob1_odr_addr &= ~(1 << 1);
        delay(100000);
        gpiob1_odr_addr |= (1 << 1);
        delay(100000);
    }
    return 0;
}